Added a new spacer component to the navigation package, allowing for the insertion of a spacer element in the navigation.

[thejmitchener]

Introduces a new spacer component to the navigation package, enabling the insertion of a spacer element within the navigation. By adding this spacer component, users can now easily include a spacer element in their navigation layout to achieve better spacing and alignment.

The changes include:

• Addition of the spacer view publishing option in the README.md file.
• Creation of the spacer.blade.php file defining the spacer component's HTML structure.
• Inclusion of the Spacer class in NavigationServiceProvider.php to handle the rendering of the spacer component.
• Implementation of the Spacer class in Spacer.php to define the component's behavior.

With this new spacer component, users can enhance the visual appearance and layout of their navigation elements, contributing to a more flexible and customizable navigation experience within the project.